When repairing disc brakes and replacing brake pads it is generally preferred to cut the brake surface of the brake rotor to true the rotor and create a smooth finish free of scratches and grooves to improve braking efficiency. The brake or friction surface is normally cut by placing the rotor on a brake rotor lathe, which turns the rotor at high speeds, and running a cutting tool across the friction surface of the rotor to make an even cut with very close tolerances.
After the friction surface of the rotor is cut, it is desirable to create a finish on the surface to improve friction between the brake pad and the friction surface. Generally, the desired finish is created on the friction surface by hand sanding the surface with a fine or medium grit sand or emery paper or using a mechanical sander about the friction surface. The procedure must be carried out on each side of the rotor separately.
An example of a mechanical grinder that is mounted on a lathe for grinding rotor surfaces is shown in U.S. Pat. No. 3,500,589 to Ellege. The device is fixedly mounted to the lathe on the tool carriage and includes a base and a support bar on which the grinding tool is mounted. The Ellege device requires manual movement of the support bar on which the grinding tool is mounted from one side of the base to the other to grind both sides of a rotor. Also, engagement of the grinding disc with the surfaces requires movement of the entire tool carriage.
The current methods require additional time-consuming, manual steps to create a finish on the rotor friction surfaces. Therefore, it is an object of the present invention to create a quick and efficient non-directional finish on the friction surfaces on each side of a rotor while the rotor is still on the rotor lathe.
It is a further object of this invention to provide such a finish with a device that will operate either with or without an external power source.
It is yet another object of the present invention to provide a device for creating a non-directional finish on a brake rotor which attaches to the rotor lathe, folds out of the way of the user for storage during cutting of the rotor and unfolds into position for finishing the friction surfaces before the rotor is removed from the lathe.
It is another object of the invention to provide a rotor finishing device with replaceable finishing surfaces that needs minimal maintenance.